feat(storefront): homepage, module gating, widget protocol, i18n fixes

Storefront homepage & module gating:
- CMS owns storefront GET / (slug="home" with 3-tier resolution)
- Catalog loses GET / (keeps /products only)
- Store root redirect (GET / → /store/dashboard or /store/login)
- Route gating: non-core modules return 404 when disabled for platform
- Seed store default homepages per platform

Widget protocol for customer dashboard:
- StorefrontDashboardCard contract in widgets.py
- Widget aggregator get_storefront_dashboard_cards()
- Orders and Loyalty module widget providers
- Dashboard template renders contributed cards (no module names)

Landing template module-agnostic:
- CTAs driven by storefront_nav (not hardcoded module names)
- Header actions check nav item IDs (not enabled_modules)
- Remove hardcoded "Add Product" sidebar button
- Remove all enabled_modules checks from storefront templates

i18n fixes:
- Title placeholder resolution ({{store_name}}) for store default pages
- Storefront nav label_keys prefixed with module code
- Add storefront.account.* keys to 6 modules (en/fr/de/lb)
- Header/footer CMS pages use get_translated_title(current_language)
- Footer labels use i18n keys instead of hardcoded English

Icon cleanup:
- Standardize on map-pin (remove location-marker alias)
- Replace all location-marker references across templates and docs

Docs:
- Storefront builder vision proposal (6 phases)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/modules/cms/routes/pages/storefront.py

@@ -28,6 +28,71 @@ ROUTE_CONFIG = {
 }
 
 
+# ============================================================================
+# STOREFRONT HOMEPAGE
+# ============================================================================
+
+
+@router.get("/", response_class=HTMLResponse, include_in_schema=False)
+async def storefront_homepage(
+    request: Request,
+    db: Session = Depends(get_db),
+):
+    """
+    Storefront homepage handler.
+
+    Looks for a CMS page with slug="home" (store override → store default),
+    and renders the appropriate landing template. Falls back to the default
+    landing template when no CMS homepage exists.
+    """
+    store = getattr(request.state, "store", None)
+    platform = getattr(request.state, "platform", None)
+    store_id = store.id if store else None
+    if not platform:
+        raise HTTPException(status_code=400, detail="Platform context required")
+
+    # Try to load a homepage from CMS (store override → store default)
+    page = content_page_service.get_page_for_store(
+        db,
+        platform_id=platform.id,
+        slug="home",
+        store_id=store_id,
+        include_unpublished=False,
+    )
+
+    # Resolve placeholders for store default pages (title + content)
+    page_content = None
+    page_title = None
+    if page:
+        page_content = page.content
+        page_title = page.title
+        if page.is_store_default and store:
+            page_content = content_page_service.resolve_placeholders(
+                page.content, store
+            )
+            page_title = content_page_service.resolve_placeholders(
+                page.title, store
+            )
+
+    context = get_storefront_context(request, db=db, page=page)
+    if page_content:
+        context["page_content"] = page_content
+    if page_title:
+        context["page_title"] = page_title
+
+    # Select template based on page.template field (or default)
+    template_map = {
+        "full": "cms/storefront/landing-full.html",
+        "modern": "cms/storefront/landing-modern.html",
+        "minimal": "cms/storefront/landing-minimal.html",
+    }
+    template_name = "cms/storefront/landing-default.html"
+    if page and page.template:
+        template_name = template_map.get(page.template, template_name)
+
+    return templates.TemplateResponse(template_name, context)
+
+
 # ============================================================================
 # DYNAMIC CONTENT PAGES (CMS)
 # ============================================================================
@@ -103,10 +168,13 @@ async def generic_content_page(
 
     # Resolve placeholders in store default pages ({{store_name}}, etc.)
     page_content = page.content
+    page_title = page.title
     if page.is_store_default and store:
         page_content = content_page_service.resolve_placeholders(page.content, store)
+        page_title = content_page_service.resolve_placeholders(page.title, store)
 
     context = get_storefront_context(request, db=db, page=page)
+    context["page_title"] = page_title
     context["page_content"] = page_content
 
     # Select template based on page.template field